Immobilization Impact of Photocatalysts onto Graphene Oxide

Abstract

The densely functionalized graphene oxide (GO) surface and the two-dimensional carbon structure had provided a unique opportunity for supporting photocatalysts. Concerning GO-based photocatalysis, GO plays the role of an electron acceptor that accelerates the interfacial electron-transfer process, recombination retardant of charge carriers, finetuner for the electronic and chemical properties of the supported photocatalysts, and finally, a carrier transport between different active sites. Moreover, standalone GO is a p-doped semiconductor material with the π* orbital of the oxygen remains as the conduction band minimum (CBM) while the valance band maximum (VBM) changes gradually from the p-orbital of carbon to the 2p orbital of oxygen upon oxidation. The outstanding features of the GO-based photocatalysis opened the way to serve the progress in many environmental applications including water treatment, air purification, water splitting, CO 2 conversion, and sensing applications.

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“…This is due to its high surface area and the presence of epoxides and hydroxyl groups, which enable the binding of active sites. Fortunately, by further chemical modification or functionalization, oxygenated groups can greatly expand the structural/chemical diversity of GO, providing an effective way to tailor the physical and chemical properties of GO to expected extents [21].…”

Photocatalytic Degradation of Dissolved Phenol by Immobilized Zinc Oxide Nanoparticles: Batch Studies, Continuous Flow Experiments, and Numerical Modeling

“…However, under continuous flow conditions, it would be necessary to separate the photocatalyst particles from the solution, before reusing them, which is a cost-expensive and energy-intensive step. Alternatively, the photocatalyst particles could be immobilized on various types of substrates, with some examples: clay [ 14 ], foams [ 15 , 16 , 17 ], graphene oxides [ 18 ], and borosilicate spheres [ 19 ]. The main disadvantage of such an approach is the reduction of photocatalytic efficiency, due to the decrease of the specific surface area, and mass transfer limitations [ 20 , 21 ].…”